The subject matter described herein relates generally to improved analyte monitoring systems, as well as methods and devices relating thereto.
The detection and/or monitoring of analyte levels, such as glucose, ketones, lactate, oxygen, hemoglobin A1C, albumin, alcohol, alkaline phosphatase, alanine transaminase, aspartate aminotransferase, bilirubin, blood urea nitrogen, calcium, carbon dioxide, chloride, creatinine, hematocrit, lactate, magnesium, oxygen, pH, phosphorus, potassium, sodium, total protein, uric acid, etc., or the like, can be important to the health of an individual having diabetes. Patients suffering from diabetes mellitus can experience complications including loss of consciousness, cardiovascular disease, retinopathy, neuropathy, and nephropathy. Diabetics are generally required to monitor their glucose levels to ensure that they are being maintained within a clinically safe range, and may also use this information to determine if and/or when insulin is needed to reduce glucose levels in their bodies, or when additional glucose is needed to raise the level of glucose in their bodies.
Growing clinical data demonstrates a strong correlation between the frequency of glucose monitoring and glycemic control. Despite such correlation, however, many individuals diagnosed with a diabetic condition do not monitor their glucose levels as frequently as they should due to a combination of factors including convenience, testing discretion, pain associated with glucose testing, and cost.
To increase patient adherence to a plan of frequent glucose monitoring, in vivo analyte monitoring systems can be utilized, in which a sensor control device may be worn on the body of an individual who requires analyte monitoring. To increase comfort and convenience for the individual, the sensor control device may have a small form-factor and can be applied by the individual with a sensor applicator. The application process includes inserting at least a portion of a sensor that senses a user's analyte level in a bodily fluid located in a layer of the human body, using an applicator or insertion mechanism, such that the sensor comes into contact with a bodily fluid. The sensor control device may also be configured to transmit analyte data to another device, from which the individual, her health care provider (“HCP”), or a caregiver can review the data and make therapy decisions.
Despite their advantages, however, some people are reluctant to use analyte monitoring systems for various reasons, including the complexity and volume of data presented, a learning curve associated with the software and user interfaces for analyte monitoring systems, and an overall paucity of actionable information presented.
Thus, needs exist for improved digital and graphical user interfaces for analyte monitoring systems, as well as methods and devices relating thereto, that are robust, user-friendly, and provide for timely and actionable responses.
The purpose and advantages of the disclosed subject matter will be set forth in and apparent from the description that follows, as well as will be learned by practice of the disclosed subject matter. Additional advantages of the disclosed subject matter will be realized and attained by the methods and systems particularly pointed out in the written description and claims hereof, as well as from the appended drawings.
The achieve these and other advantages and in accordance with the purpose of the disclosed subject matter, as embodied and broadly described, the disclosed subject matter is directed to systems monitoring glucose. According to an embodiment, a system for monitoring glucose can include a sensor control device and a reader device. The sensor control device can include an analyte sensor coupled with sensor electronics and can be configured to transmit data indicative of an analyte level of a subject. The reader device can include a wireless communication circuitry configured to receive the data indicative of the analyte level and a glycated hemoglobin level for the subject, a non-transitory memory, at least one processor communicatively coupled to the non-transitory memory and the analyte sensor and configured to calculate a plurality of personalized glucose metrics for the subject using at least one physiological parameter and at least one of the received data indicative of the analyte level or the received glycated hemoglobin level, and display, on a display of the reader device, a report comprising a plurality of interfaces including at least two or more of the received data indicative of the analyte level, the received glycated hemoglobin level, or the calculated plurality of personalized glucose metrics, wherein the plurality of interfaces comprising the report are based on a user type.
As embodied herein, the plurality of personalized glucose metrics can include one or more of an adjusted A1c or personalized A1c, a calculated A1c, an adjusted calculated A1c, a personalized glucose, a personalized average glucose, or a personalized time in range. Further, the at least one processor can be configured to calculate a plurality of personalized glucose targets corresponding to the calculated plurality of personalized glucose metrics. The plurality of interfaces can further include the plurality of personalized glucose targets. Additionally, the plurality of personalized glucose targets can include one or more of a target glucose range or a target average glucose. As embodied herein, the personalized target glucose range can include a personalized lower glucose limit. Alternatively, the personalized target glucose range can include a personalized upper glucose limit.
As embodied herein, the at least one physiological parameter can be selected from the group consisting of: a red blood cell glucose uptake, a red blood cell lifespan, a red blood cell glycation rate constant, a red blood cell generation rate constant, a red blood cell elimination constant, and an apparent glycation constant. Further, the plurality of interfaces can include the at least one physiological parameter for the subject.
As embodied herein, the user type can include a health care professional. Further, the plurality of interfaces can include a glucose monitoring data interface, a glycated hemoglobin interface, a personalized a1c interface, a personalized glucose interface, a personalized average glucose, and a personalized time in range interface.
As embodied herein, the user type can include the subject. Further, the plurality of interfaces can include a glucose monitoring data interface, a glycated hemoglobin interface, a mean glucose interface, and a time in range interface.
As embodied herein, the plurality of interfaces comprising the report can be predetermined based on the user type.
As embodied herein, the plurality of interfaces comprising the report can be selected by the user.
As embodied herein, the at least one processor can be further configured to output a notification if at least one of the plurality of personalized glucose metrics is at or above the corresponding plurality of personalized glucose targets. As embodied herein, the notification can be a visual notification. Alternatively, the notification can be an audio notification. The notification can also be an alarm. As embodied herein, the notification can be a prompt.
As embodied herein, the reader device can wirelessly receive the glycated hemoglobin level for the subject from an electronic medical records system.
As embodied herein, the reader device can wirelessly receive the glycated hemoglobin level for the subject from a cloud-based database.
As embodied herein, the reader device can wirelessly receive the glycated hemoglobin level for the subject from a QR code.
As embodied herein, the reader device can wirelessly receive the glycated hemoglobin level for the subject from a home test kit.
The details of the subject matter set forth herein, both as to its structure and operation, may be apparent by study of the accompanying figures, in which like reference numerals refer to like parts. The components in the figures are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the subject matter. Moreover, all illustrations are intended to convey concepts, where relative sizes, shapes and other detailed attributes may be illustrated schematically rather than literally or precisely.
Before the present subject matter is described in detail, it is to be understood that this disclosure is not limited to the particular embodiments described, as such may, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting, since the scope of this disclosure will be limited only by the appended claims.
As used herein and in the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise.
The publications discussed herein are provided solely for their disclosure prior to the filing date of this application. Nothing herein is to be construed as an admission that this disclosure is not entitled to antedate such publication by virtue of prior disclosure. Further, the dates of publication provided may be different from the actual publication dates which may need to be independently confirmed.
Generally, embodiments of this disclosure include GUIs and digital interfaces for analyte monitoring systems, and methods and devices relating thereto. Accordingly, many embodiments include in vivo analyte sensors structurally configured so that at least a portion of the sensor is, or can be, positioned in the body of a user to obtain information about at least one analyte of the body. It should be noted, however, that the embodiments disclosed herein can be used with in vivo analyte monitoring systems that incorporate in vitro capability, as well as purely in vitro or ex vivo analyte monitoring systems, including systems that are entirely noninvasive.
Furthermore, for each and every embodiment of a method disclosed herein, systems and devices capable of performing each of those embodiments are covered within the scope of this disclosure. For example, embodiments of sensor control devices, reader devices, local computer systems, and trusted computer systems are disclosed, and these devices and systems can have one or more sensors, analyte monitoring circuits (e.g., an analog circuit), memories (e.g., for storing instructions), power sources, communication circuits, transmitters, receivers, processors and/or controllers (e.g., for executing instructions) that can perform any and all method steps or facilitate the execution of any and all method steps.
As previously described, a number of embodiments described herein provide for improved GUIs for analyte monitoring systems, wherein the GUIs are highly intuitive, user-friendly, and provide for rapid access to physiological information of a user. According to some embodiments, a Time-in-Ranges GUI of an analyte monitoring system is provided, wherein the Time-in-Ranges GUI comprises a plurality of bars or bar portions, wherein each bar or bar portion indicates an amount of time that a user's analyte level is within a predefined analyte range correlating with the bar or bar portion. According to another embodiment, an Analyte Level/Trend Alert GUI of an analyte monitoring system is provided, wherein the Analyte Level/Trend Alert GUI comprises a visual notification (e.g., prompts, alert, alarm, pop-up window, banner notification, etc.), and wherein the visual notification includes an alarm condition, an analyte level measurement associated with the alarm condition, and a trend indicator associated with the alarm condition. In sum, these embodiments provide for a robust, user-friendly interfaces that can increase user engagement with the analyte monitoring system and provide for timely and actionable responses by the user, to name a few advantages.
In addition, a number of embodiments described herein provide for improved digital interfaces for analyte monitoring systems. According to some embodiments, improved methods, as well as systems and device relating thereto, are provided for data backfilling, aggregation of disconnection and reconnection events for wireless communication links, expired or failed sensor transmissions, merging data from multiple devices, transitioning of previously activated sensors to new reader devices, generating sensor insertion failure system alarms, and generating sensor termination system alarms. Collectively and individually, these digital interfaces improve upon the accuracy and integrity of analyte data being collected by the analyte monitoring system, the flexibility of the analyte monitoring system by allowing users to transition between different reader devices, and the alarming capabilities of the analyte monitoring system by providing for more robust inter-device communications during certain adverse conditions, to name only a few. Other improvements and advantages are provided as well. The various configurations of these devices are described in detail by way of the embodiments which are only examples.
Before describing these aspects of the embodiments in detail, however, it is first desirable to describe examples of devices that can be present within, for example, an in vivo analyte monitoring system, as well as examples of their operation, all of which can be used with the embodiments described herein.
There are various types of in vivo analyte monitoring systems. “Continuous Analyte Monitoring” systems (or “Continuous Glucose Monitoring” systems), for example, can transmit data from a sensor control device to a reader device continuously without prompting, e.g., automatically according to a schedule. “Flash Analyte Monitoring” systems (or “Flash Glucose Monitoring” systems or simply “Flash” systems), as another example, can transfer data from a sensor control device in response to a scan or request for data by a reader device, such as with a Near Field Communication (NFC) or Radio Frequency Identification (RFID) protocol. In vivo analyte monitoring systems can also operate without the need for finger stick calibration.
In vivo analyte monitoring systems can be differentiated from “in vitro” systems that contact a biological sample outside of the body (or “ex vivo”) and that typically include a meter device that has a port for receiving an analyte test strip carrying bodily fluid of the user, which can be analyzed to determine the user's blood sugar level.
In vivo monitoring systems can include a sensor that, while positioned in vivo, makes contact with the bodily fluid of the user and senses the analyte levels contained therein. The sensor can be part of the sensor control device that resides on the body of the user and contains the electronics and power supply that enable and control the analyte sensing. The sensor control device, and variations thereof, can also be referred to as a “sensor control unit,” an “on-body electronics” device or unit, an “on-body” device or unit, or a “sensor data communication” device or unit, to name a few.
In vivo monitoring systems can also include a device that receives sensed analyte data from the sensor control device and processes and/or displays that sensed analyte data, in any number of forms, to the user. This device, and variations thereof, can be referred to as a “handheld reader device,” “reader device” (or simply a “reader”), “handheld electronics” (or simply a “handheld”), a “portable data processing” device or unit, a “data receiver,” a “receiver” device or unit (or simply a “receiver”), or a “remote” device or unit, to name a few. Other devices such as personal computers have also been utilized with or incorporated into in vivo and in vitro monitoring systems.
Additional details of suitable analyte monitoring devices, systems, methods, components and the operation thereof along with related features are set forth in U.S. Pat. No. 9,913,600 to Taub et. al., International Publication No. WO2018/136898 to Rao et. al., International Publication No. WO2019/236850 to Thomas et. al., and U.S. Patent Publication No. 2020/01969191 to Rao et al., each of which is incorporated by reference in its entirety herein.
A memory 163 is also included within ASIC 161 and can be shared by the various functional units present within ASIC 161, or can be distributed amongst two or more of them. Memory 163 can also be a separate chip. Memory 163 can be volatile and/or non-volatile memory. In this embodiment, ASIC 161 is coupled with power source 170, which can be a coin cell battery, or the like. AFE 162 interfaces with in vivo analyte sensor 104 and receives measurement data therefrom and outputs the data to processor 166 in digital form, which in turn processes the data to arrive at the end-result glucose discrete and trend values, etc. This data can then be provided to communication circuitry 168 for sending, by way of antenna 171, to reader device 120 (not shown), for example, where minimal further processing is needed by the resident software application to display the data. According to some embodiments, for example, a current glucose value can be transmitted from sensor control device 102 to reader device 120 every minute, and historical glucose values can be transmitted from sensor control device 102 to reader device 120 every five minutes.
In some embodiments, to conserve power and processing resources on sensor control device 102, digital data received from AFE 162 can be sent to reader device 120 (not shown) with minimal or no processing. In still other embodiments, processor 166 can be configured to generate certain predetermined data types (e.g., current glucose value, historical glucose values) either for storage in memory 163 or transmission to reader device 120 (not shown), and to ascertain certain alarm conditions (e.g., sensor fault conditions), while other processing and alarm functions (e.g., high/low glucose threshold alarms) can be performed on reader device 120. Those of skill in the art will understand that the methods, functions, and interfaces described herein can be performed—in whole or in part—by processing circuitry on sensor control device 102, reader device 120, local computer system 170, or trusted computer system 180.
Described herein are example embodiments of GUIs for analyte monitoring systems. As an initial matter, it will be understood by those of skill in the art that the GUIs described herein comprise instructions stored in a memory of reader device 120, local computer system 170, trusted computer system 180, and/or any other device or system that is part of, or in communication with, analyte monitoring system 100. These instructions, when executed by one or more processors of the reader device 120, local computer system 170, trusted computer system 180, or other device or system of analyte monitoring system 100, cause the one or more processors to perform the method steps and/or output the GUIs described herein. Those of skill in the art will further recognize that the GUIs described herein can be stored as instructions in the memory of a single centralized device or, in the alternative, can be distributed across multiple discrete devices in geographically dispersed locations.
Described herein are example embodiments of exemplary embodiments of models for personalized glucose-related metrics. The present disclosure generally describes methods, devices, and systems for determining physiological parameters related to the kinetics of red blood cell glycation, elimination, and generation and reticulocyte maturation within the body of a subject. Such physiological parameters can be used, for example, to calculate a more reliable calculated HbA1c (cHbA1c), adjusted or personalized HbA1c (aHbA1c), adjusted calculated HbA1c (acHbA1c), and/or a personalized target glucose range, among other things, for subject-personalized diagnoses, treatments, and/or monitoring protocols.
Herein, the terms “HbA1c level,” “HbA1c value,” and “HbA1c” are used interchangeably. Herein, the terms “personalized A1c,” “personalized HbA1c,” “aHbA1c level,” “aHbA1c value,” and “aHbA1c” are used interchangeably. Herein, the terms “cHbA1c level,” “cHbA1c value,” “cHbA1c,” and “GD-Ale” are used interchangeably and/or a personalized target glucose range, among other things. Herein, the terms “acHbA1c level,” “acHbA1c value,” and “acHbA1c,” are used interchangeably.
High glucose exposure in specific organs (particularly eye, kidney and nerve) is a critical factor for the development of diabetes complications. A laboratory HbA1c (also referred to in the art as a measured HbA1c) is routinely used to assess glycemic control, but studies report a disconnect between this glycemic marker and diabetes complications in some individuals. The exact mechanisms for the failure of laboratory HbA1c to predict diabetes complications are not often clear but likely in some cases to be related to inaccurate estimation of intracellular glucose exposure in the affected organs.
Formula 1 illustrates the kinetics of red blood cell hemoglobin glycation (or referred to herein simply as red blood cell glycation), red blood cell elimination, and red blood cell generation, where “G” is free glucose, “R” is a non-glycated red blood cell, and “GR” is glycated red blood cell hemoglobin. The rate at which glycated red blood cell hemoglobin (GR) are formed is referred to herein as a red blood cell hemoglobin glycation rate constant (kgly typically having units of dl_*mg−1*day1).
Over time, red blood cells including the glycated red blood cells are continuously eliminated from a subject's circulatory system and new red blood cells are generated, typically at a rate of approximately 2 million cells per second. The rates associated with elimination and generation are referred to herein as a red blood cell elimination constant (kage typically having units of day−1) and a red blood cell generation rate constant (kgen typically having units of M2/day), respectively. Since the amount of red blood cells in the body is maintained at a stable level most of time, the ratio of kage and kgen should be an individual constant that is the square of red blood cell concentration.
Relative to glycation, Formula 2 illustrates the mechanism in more detail where glucose transporter 1 (GLUT1) facilitates glucose (G) transport into the red blood cell. Then, the intracellular glucose (GI) interacts with the hemoglobin (Hb) to produce glycated hemoglobin (HbG) where the hemoglobin glycation reaction rate constant is represented by kg (typically having units of dl_*mg−1*day1). A typical experiment measured kg value is 1.2×103 db/mg/day. Hemoglobin glycation reaction is a multi-step non-enzymatic chemical reaction, therefore kg should be a universal constant. The rate constant for the glucose to be transported into the red blood cell and glycated the Hb into HbG is kgly. Then, kage describes red blood cell elimination (along with hemoglobin), also described herein as the red blood cell turnover rate.
While raised intracellular glucose is responsible for diabetes complications, extracellular hyperglycemia selectively damages cells with limited ability to adjust cross-membrane glucose transport effectively. HbA1c has been used as a biomarker for diabetes-related intracellular hyperglycemia for two main reasons. First, the glycation reaction occurs within red blood cells (RBCs) and therefore HbA1c is modulated by intracellular glucose level. Second, RBCs do not have the capacity to adjust glucose transporter GLUT1 levels and thus are unable to modify cross-membrane glucose uptake, behaving similarly to cells that are selectively damaged by extracellular hyperglycemia. Therefore, under conditions of fixed RBC lifespan and cross-membrane glucose uptake, HbA1c mirrors intracellular glucose exposure in organs affected by diabetes complications. However, given the inter-individual variability in both cross-membrane glucose uptake and RBC lifespan, laboratory HbA1c may not always reflect intracellular glucose exposure. While variation in RBC cross-membrane glucose uptake is likely to be relevant to the risk of estimating diabetes complications in susceptible organs, red blood cell lifespan is unique to RBCs and therefore irrelevant to the complication risk in other tissues. This explains the inability to clinically rely on laboratory HbA1c in those with hematological disorders characterized by abnormal RBC turnover and represents a possible explanation for the apparent “disconnect” between laboratory HbA1c and development of complications in some individuals with diabetes (
To overcome the limitations of laboratory HbA1c, a measure of personalized HbA1c has been developed, which takes into account individual variations in both RBC turnover and cellular glucose uptake. The current work aims to extend this model by adjusting for a standard RBC lifespan of 100 days (equivalent to RBC turnover rate of 1% per day, or mean RBC age of 50 days) to establish a new clinical marker, which we term adjusted HbA1c (aHbA1c). We propose that aHbA1c is the most relevant glycemic marker for estimating organ exposure to hyperglycemia and risk of future diabetes-related complications
As described previously, HbA1c is a commonly used analyte indicative of the fraction of the glycated hemoglobin found in red blood cells. Therefore, a kinetic model can be used, for example, to derive a calculated HbA1c based on at least the glucose levels measured for a subject. However, the kinetic model can also be applied to HbA1. For simplicity, HbA1c is uniformly used herein, but HbA1 could be substituted except in instances where specific HbA1c values are used (e.g., see Equations 15 and 16). In such instances, specific HbA1 values could be used to derive similar equations.
Typically, when kinetically modeling physiological processes, assumptions are made to focus on the factors that affect the physiological process the most and simplify some of the math.
The present disclosure uses only the following set of assumptions to kinetically model the physiological process illustrated in Formula 1. First, glucose concentration is high enough not to be affected by the red blood cell glycation reaction. Second, there is an absence of abnormal red blood cells that would affect HbA1c measurement, so the hematocrit is constant for the period of interest. This assumption was made to exclude extreme conditions or life events that are not normally present and may adversely affect the accuracy of the model. Third, the glycation process has first order dependencies on both red blood cell and glucose concentrations. Fourth, newly-generated red blood cells have a negligible amount of glycated hemoglobin, based on previous reports that reticulocyte HbA1c is very low and almost undetectable. Fifth, red blood cell production inversely correlates with total cellular concentration, whereas elimination is a first order process.
With the five assumptions described above for this kinetic model, the rate of change in glycated and non-glycated red blood cells can be modeled by differential Equations 1 and 2.
C is the whole population of red blood cells, where C=[ff]+[GR](Equation 2a). C typically has units of M (mol/L), [R] and [GR] typically have units of M, and [G] typically has units of mg/dl_.
Assuming a steady state, where the glucose level is constant and the glycated and non-glycated red blood cell concentrations remain stable (d[GR]/dt=(d[R])/dt=0), the following two equations can be derived. Equation 3 defines the apparent glycation constant K (typically with units of dL/mg) as the ratio of kgly and kage, whereas Equation 4 establishes the dependency between red blood cell generation and elimination rates.
For simplicity, kage is used hereafter to describe the methods, devices, and systems of the present disclosure. Unless otherwise specified, kgen can be substituted for kage. To substitute kgen for kage, Equation 4 would be rearranged to kgen−kage*C.
HbA1c is the fraction of glycated hemoglobin as shown in Equation 5.
In a hypothetical state when a person infinitely holds the same glucose level, HbA1c in Equation 5 can be defined as “equilibrium HbA1c” (EA) (typically reported as a % (e.g., 6.5%) but used in decimal form (e.g., 0.065) in the calculations). For a given glucose level, EA (Equation 6) can be derived from Equations 2a, 3, and 5.
EA is an estimate of HbA1c based on a constant glucose concentration [G] for a long period. This relationship effectively approximates the average glucose and HbA1c for an individual having a stable day-to-day glucose profile. EA depends on K, the value of which is characteristic to each subject. Equation 6 indicates that the steady glucose is not linearly correlated with EA. Steady glucose and EA may be approximated with a linear function within a specific range of glucose level, but not across the full typical clinical range of HbA1c. Furthermore, in real life with continuous fluctuations of glucose levels, there is no reliable linear relationship between laboratory HbA1c and average glucose for an individual.
Others have concluded this also and produced kinetic models to correlate a measured HbA1c value to average glucose levels. For example, The American Diabetes Association has an online calculator for converting HbA1c values to estimated average glucose levels. However, this model is based on an assumption that kage and kgly do not substantially vary between subjects, which is illustrated to be false in Example 1 below. Therefore, the model currently adopted by the American Diabetes Association considers kage and kgly as constants and not variable by subject.
A more recent model by Higgens et al. (Sci. Transl. Med. 8, 359ral30, 2016) has been developed that removed the assumption that red blood cell life is constant. However, the more recent model still assumes that kgly does not substantially vary between subjects.
In contrast, both kage and kgly are variables for the kinetic models described herein. Further, a subject's kgly is used in some embodiments to derive personalized parameters relating to the subject's diabetic condition and treatment (e.g., a medication dosage, a supplement dosage, an exercise plan, a diet/meal plan, and the like).
Continuing with the kinetic model of the present disclosure, the HbA1c value (HbA1ct) at the end of a time period t (Equation 7) can be derived from Equation 1, given a starting HbA1c (HbA1co) and assuming a constant glucose level [G] during the time period.
To accommodate changing glucose levels over time, each individual's glucose history is approximated as a series of time intervals t, with corresponding average glucose levels [G,]. Applying Equation 7 recursively, HbAlCz at the end of time interval tz can be expressed by Equation 8 for numerical calculations.
Equation 8 where the decay term Dt=e−(y[G;]+/cage)t£ (Equation 8a).
When solving for kage and kgly using Equations 6, 7, or 8, kage and kgly may be bounded to reasonable physiological limits, by way of nonlimiting example, of 5.0*106 dl_*mg{circumflex over ( )}day−1<kgly<8.0*106 dl_*mg{circumflex over ( )}day1 and 0.006 day1<kage<0.024 day−1. Additionally or alternatively, an empirical approach using the Broyden-Fletcher-Goldfarb-Shanno algorithm can be used with estimated initial values for kgly and kage (e.g., kgly=4.4*10−6 dl_*mg{circumflex over ( )}day1 and kage=0.0092 dayx). The more glucose level data points and measured HbA1c data points, the more accurate the physiological parameters described herein are.
The value for time interval t, can be selected (e.g., by a user or developer, or by software instructions being executed on one or more processors) based on a number of factors that can vary between embodiments and, as such, the value of time interval t may vary. One such factor is the duration of time from one glucose data value (e.g., a measured glucose level at a discrete time, a value representative of glucose level for a particular time period across multiple discrete times, or otherwise) to another within the individual's glucose history. That duration of time between glucose data values can be referred to as time interval tg. Time interval tg can vary across the individual's glucose history such that a single glucose history can have a number of different values for time interval tg. Numerous example embodiments leading to different values of time interval tg are described herein. In some embodiments of glucose monitoring systems, glucose data points are determined after a fixed time interval tg (e.g., every minute, every ten minutes, every fifteen minutes, etc.) and the resulting glucose history is a series of glucose data points with each point representing the glucose at the expiration of or across the fixed time interval tg (e.g., a series of glucose data points at one minute intervals, etc.). [0037] In other embodiments, glucose data points are taken or determined at multiple different fixed time intervals tg. For example, in some flash analyte monitoring systems (described in further detail herein), a user may request glucose data from a device (e.g., a sensor control device) that stores glucose data within a recent time period (e.g., the most recent fifteen minutes, the most recent hour, etc.) at a first relatively shorter time interval tg (e.g., every minute, every two minutes), and all other data (in some cases up to a maximum of eight hours, twelve hours, twenty-four hours, etc.) outside of that recent time period is stored at a second relatively longer time interval tg (e.g., every ten minutes, every fifteen minutes, every twenty minutes, etc.). The data stored at the second, relatively longer time interval can be determined from data originally taken at the relatively shorter time interval tg (e.g., an average, median, or other algorithmically determined value). In such an example the resulting glucose history is dependent on how often a user requests glucose data, and can be a combination of some glucose data points at the first time interval tg and others at the second time interval tg. Of course, more complex variations are also possible with, for example, three or more time intervals tg. In some embodiments, glucose data collected with ad hoc adjunctive measurements (e.g., a finger stick and test strip) can also be present, which can result in even more variations of time interval tg.
An example analysis performed on glucose histories for a sample of subjects (approximately 400) where glucose data points were generally present at time intervals tg of one to fifteen minutes, indicated that a value for time interval t, within the range of three hours (or about three hours) to twenty four hours (or about twenty four hours) could be selected without significant loss of accuracy. Generally, shorter time intervals t, resulted in higher accuracy than longer ones, and time interval t, values closer to three hours were the most accurate. Time interval t, values less than three hours may begin to exhibit loss of accuracy due to numerical rounding errors. These rounding errors can be reduced by using longer digit strings at the expense of processing load and computing time. It should be noted that other values of time interval t, outside of the range of 3 to 24 hours may be suitable depending on the desired accuracy levels and other factors, such as the average time interval tg between glucose data points.
Another factor in selection of time interval t, is the existence of gaps, or missing data, in the individual's glucose history, where the gaps are longer or significantly longer than the longest time interval tg. The existence of one or more such gaps can potentially lead to results bias. These gaps can result, for example, from the inability to collect glucose data across a certain time period (e.g., the user was not wearing a sensor, the user forgot to scan the sensor for data, a fault occurred, etc.). The presence of gaps and their duration should be considered in selecting time interval t. Generally, the number and duration of gaps should be minimized (or eliminated) where possible. But since gaps of this type are often difficult to eliminate, to the extent such gaps exist, in many embodiments the selection of time interval t, should be at least twice the duration of the largest (maximum) gap between glucose data points. For example, if time interval t, is selected to be 3 hours, then the maximum gap should be no longer than 90 minutes, if time interval t, is selected to be 24 hours, then the largest gap should be no longer than 12 hours, and so forth.
The value HbA1cz is the estimated HbA1c of the present kinetic model, which is referred to herein as cHbA1c (calculated HbA1c) to distinguish from other eHbA1c described herein.e
As described previously and illustrated in Equation 8, EA, and D, are both affected by glucose level [G,], kgly, and kage. In addition, D, depends on the length of the time interval t. Equation 8 is the recursive form of Equation 7. Equations 7 and 8 describe the relationship among HbA1c, glucose level, and individual red blood cell kinetic constants kgly and kage.
kage can be directly measured through expensive and laborious methods. Herein, the kinetic model is extended to incorporate reticulocyte maturation as a method for estimating kage.
Reticulocytes are immature red blood cells and typically account for about 1% of the total red blood cells. The rate at which reticulocytes mature into mature red blood cells is kmat (typically having units of day−1). The maturation half-life for a normal reticulocyte is about 4.8 hours, which provides for Equation 9.
The kinetic model makes two assumptions: (1) all red blood cells are reticulocytes at time 0 and (2) reticulocytes are not eliminated (that is, reticulocytes mature to mature red blood cells and do not die). The probability density of reticulocyte age (PRET) can be represented by Equation 10.
A reticulocyte production index (RPI), also known as a corrected reticulocyte count (CRC), is the percentage of total red blood cells that are reticulocytes. Therefore, RPI is the integral of PRET over cell age as shown in Equation 11, where RPI is the decimal form of the reported RPI (e.g., RPI reported at 2% is 0.02 in Equation 11).
Assuming the typical kmat is 3.47 day−1, kage can be estimated from a measured RPI. RPI can be determined by normal methods. For example, RPI can be determined by measuring a hematocrit percentage (HMm), measuring a percentage of reticulocytes (RP) in an RNA dyed blood smear, determining a maturation correction (MC) from the measured hematocrit percentage, and calculating the RPI based on Equation 12, where RP and HMm is used as the percentage values not the decimal form (i.e., RP reported at 3% is 3 in the equation not 0.03).
Assuming the typical kmat is 3.47 day−1, kage can be estimated from a measured RPI. RPI can be determined by normal methods. For example, RPI can be determined by measuring a hematocrit percentage (HMm), measuring a percentage of reticulocytes (RP) in an RNA dyed blood smear, determining a maturation correction (MC) from the measured hematocrit percentage, and calculating the RPI based on Equation 12, where RP and HMm is used as the percentage values not the decimal form (i.e., RP reported at 3% is 3 in the equation not 0.03).
RPI=(RP*HMm/HMn)/MC Equation 12 where HMn is the normal hematocrit value (typically 45).
Unless otherwise specified, the typical units described are associated with their respective values. One skilled in the art would recognize other units and the proper conversions. For example, [G] is typically measured in mg/dL but could be converted to M using the molar mass of glucose. If [G] is used in M or any other variable is used with different units, the equations herein should be adjusted to account for differences in units.
Calculating Physiological Parameters from the Kinetic Model
Embodiments of the present disclosure provide kinetic modeling of red blood cell glycation, elimination, and generation and reticulocyte maturation within the body of a subject.
The physiological parameter kage can be estimated from one or more RPI measurements. While kage can be estimated using Equation 11 above from a single RPI measurement, two or more RPI measurements may increase the accuracy of the RPI value. Further, RPI can change over time, in response to treatment, and in response to the improvement or worsening of a disease state. Therefore, while RPI can be measured be measured in any desired intervals of time (e.g., weekly to annually), preferably RPI is measured once every three to six months.
Once kage is calculated, the physiological parameters kgly and/or K can be estimated from the equations described herein given at least one measured HbA1c value (also referred to as HbA1c level measurement) and a plurality of glucose levels (also referred to as glucose level measurements) over a time period immediately before the HbA1c measurement.
The number of measured HbA1c values 12102a, 12102b, 12102c needed to calculate kgly and/or K depends on the frequency and duration of the plurality of glucose levels. The number of measured RPI values 110a, 110b, 110c needed to calculate kage depends on the stability of individual kmat and its deviation to typical kmat (3.47 day−1). Preferably RPI is measured once every three to six months but can be measured monthly or weekly, if needed.
In a first embodiment, one measured RPI value 110b can be used to calculate kage, and one measured HbA1c 12102b can be used along with the calculated kage and a plurality of glucose measurements over time period 106 to calculate kgly and/or K. Such embodiments are applicable to subjects with steady daily glucose measurements for a long time period 106 (e.g., over about 200 days). K may be calculated at time point 101 with Equation 6 by replacing EA with the measured HbA1c value 12102b and [G] with daily average glucose over time period 106. kgly may then be calculated from Equation 3. Therefore, in this embodiment, an initial HbA1c level measurement 12102a is not necessarily required.
Because a first HbA1c value is not measured, the time interval 106 of initial glucose level measurements with frequent measurements may need to be long to obtain an accurate representation of average glucose and reduce error. Using more than 100 days of steady glucose pattern for this method may reduce error. Additional length like 200 days or more or 300 days or more further reduces error.
Embodiments where one measured HbA1c value 12102b can be used include a time period 106 about 100 days to about 300 days (or longer) with glucose levels being measured at least about 72 times per day (e.g., about every 20 minutes) to about 96 times per day (e.g., about every 15 minutes) or more often. Further, in such embodiments, the time between glucose level measurements may be somewhat consistent where an interval between two glucose level measurements should not be more than about an hour. Some missing data glucose measurements are tolerable when using only one measured HbA1c value. Increases in missing data may lead to more error.
Alternatively, in some instances where one measured HbA1c value 12102b is used, the time period 106 may be shortened if a subject has an existing glucose level monitoring history with stable, consistent glucose profile. For example, for a subject who has been testing for a prolonged time (e.g., 6 months or longer) but, perhaps, at less frequent or regimented times, the existing glucose level measurements can be used to determine and analyze a glucose profile. Then, if more frequent and regimented glucose monitoring is performed over time period 106 (e.g., about 72 times to about 96 times or more per day over about 14 days or more) followed by measurement of HbA1c 12102b and RPI 110b, the four sets of data in combination may be used to calculate one or more physiological parameters (kg iy, kage, and/or K) at time point 101.
Alternatively, in some embodiments, one or more measured RPI values 110a, 110b, two measured HbA1c values (a first measured HbA1c value 12102a at the beginning of a time period 106 and a second measured HbA1c value 12102b at the end of the time period 106), and a plurality of glucose levels 12104a measured during the time period 106 may be used to calculate one or more physiological parameters (kgly, kage, and/or K) at time point 101. In these embodiments, Equation 11 may be used to calculate kage, and Equation 8 may be used to calculate kgly and/or K at time point 101. In such embodiments, the plurality of glucose levels 12104a may be measured for about 10 days to about 30 days or longer with measurements being, on average, about 4 times daily (e.g., about every 6 hours) to about 24 times daily (e.g., about every 1 hour) or more often.
In the foregoing embodiments, the RPI value(s) can be measured at a time other than as illustrated because measured RPI values are relatively stable over time. Therefore, the RPI value(s) can be measured at any time during time period 106 and be applicable to these embodiments.
The foregoing embodiments are not limited to the example glucose level measurement time period and frequency ranges provided. Glucose levels may be measured over a time period of about a few days to about 300 days or more (e.g., about one week or more, about 10 days or more, about 14 days or more, about 30 days or more, about 60 days or more, about 90 days or more, about 120 days or more, and so on). In some embodiments, the time period is 7 days or more, preferably one to ten months, and less than one year. The frequency of such glucose levels may be, on average, about 14,400 times daily (e.g., a time interval tg of about every 6 seconds) (or more often) to about 3 times daily (e.g., a time interval tg of about every 8 hours) (e.g., 1,440 times daily (e.g., a time interval tg of about every minute), about 288 times daily (e.g., a time interval tg of about every 5 minutes), about 144 times daily (e.g., a time interval tg of about every 10 minutes), about 96 times daily (e.g., a time interval tg of about every 15 minutes), about 72 times daily (e.g., a time interval tg of about every 20 minutes), about 48 times daily (e.g., a time interval tg of about every 30 minutes), about 24 times daily (e.g., a time interval tg of about every 1 hour), about 12 times daily (e.g., a time interval tg of about every 2 hours), about 8 times daily (e.g., a time interval tg of about every 3 hours), about 6 times daily (e.g., a time interval tg of about every 4 hours), about 4 times daily (e.g., a time interval tg of about every 6 hours), and so on). In some instances, less frequent monitoring (like once or twice daily) may be used where the glucose measurements occur at about the same time (within about 30 minutes) daily to have a more direct comparison of day-to-day glucose levels and reduce error in subsequent analyses.
The foregoing embodiments may further include calculating an error or uncertainty associated with the one or more physiological parameters. In some embodiments, the error may be used to determine if another HbA1c value (not illustrated) should be measured near time point 101, if one or more glucose levels 12104b should be measured (e.g., near time point 101), if the monitoring and analysis should be extended (e.g., to extend through time period 108 from time point 101 to time point 12103 including measurement of glucose levels 12104b during time period 108 and measurement of HbA1c value 12102c at time point 12103), and/or if the frequency of glucose level measurements 12104b in an extended time period 108 should be increased relative to the frequency of glucose level measurements 12104a during time period 106. In some embodiments, one or more of the foregoing actions may be taken when the error associated with kgly, kage, and/or K is at or greater than about 15%, preferably at or greater than about 10%, preferably at or greater than about 7%, and preferably at or greater than about 5%. When a subject has an existing disease condition (e.g., cardiovascular disease), a lower error may be preferred to have more stringent monitoring and less error in the analyses described herein.
Alternatively or when the error is acceptable, in some embodiments, one or more physiological parameters (kgly, kage, and/or K) at time point 101 may be used to determine one or more parameters or characteristics for a subject's personalized diabetes management (e.g., a cHbA1c at the end of time period 108, a personalized-target glucose range, and/or a treatment or change in treatment for the subject in the near future), each described in more detail further herein. In some instances, in addition to the foregoing embodiments, an HbA1c value may be measured at time point 12103 and the one or more physiological parameters recalculated and applied to a future time period (not illustrated).
Alternatively or additionally, two values for kage can be estimated using Equation 8 and Equation 11. A comparison of these two values can be used to determine if another HbA1c value (not illustrated) should be measured near time point 101, if one or more glucose levels 12104b should be measured (e.g., near time point 101), if the monitoring and analysis should be extended (e.g., to extend through time period 108 from time point 101 to time point 12103 including measurement of glucose levels 12104b and measurement of HbA1c value 12102c at time point 12103), and/or if the frequency of glucose level measurements 12104b in an extended time period 108 should be increased relative to the frequency of glucose level measurements 12104a during time period 106. For example, if the two values of kage are more than 10% different (e.g., the low value is not within 10% of the high value based on the high value), the individual's kmat may be different than the typical kmat (3.47 day−1). If a large difference is observed (e.g., more than 20% difference), the individual's kmat could be determined. If the individual's kmat is stable over a time period (e.g., three to six months), the determined individual's kmat should be used in place of the typical kmat in Equation 11 in the methods, systems, and devices described herein. Fluctuation in kmat could suggest other health problems.
The one or more physiological parameters and/or the one or more parameters or characteristics for a subject's personalized diabetes management can be measured and/or calculated for two or more times (e.g., time point 101 and time point 12103) and compared. For example, kgly at time point 101 and time point 12103 may be compared. In another example, cHbA1c at time point 12103 and at a future time may be compared. Some embodiments, described further herein, may use such comparisons to (1) monitor progress and/or effectiveness of a subject's personalized diabetes management and, optionally, alter the subject's personalized diabetes management, (2) identify an abnormal or diseased physiological condition, and/or (3) identify subjects taking supplements and/or medicines that affect red blood cell production and/or affect metabolism.
Each of the example methods, devices, and systems described herein can utilize the one or more physiological parameters (kgly, kage, and K) and perform one or more related analyses (e.g., personalized-target glucose range, personalized-target average glucose, cHbA1c, and the like). The one or more physiological parameters (kgly, kage, and K) and related analyses may be updated periodically (e.g., about every 3 months to annually). The frequency of updates may depend on, among other things, the subject's glucose level and diabetes history (e.g., how well the subject stays within the prescribed thresholds), other medical conditions, and the like.
In the embodiments described herein that apply the one or more physiological parameters (kgly, kage, and/or K), one or more other subject-specific parameters may be used in addition to the one or more physiological parameters. Examples of subject-specific parameters may include, but are not limited to, vital information (e.g., heart rate, body temperature, blood pressure, or any other vital information), body chemistry information (e.g., drug concentration, blood levels, troponin level, cholesterol level, or any other body chemistry information), meal data/information (e.g., carbohydrate amount, sugar amount, or any other information about a meal), activity information (e.g., the occurrence and/or duration of sleep and/or exercise), an existing medical condition (e.g., cardiovascular disease, heart valve replacement, cancer, and systemic disorder such as autoimmune disease, hormone disorders, and blood cell disorders), a family history of a medical condition, a current treatment, an age, a race, a gender, a geographic location (e.g., where a subject grew up or where a subject currently lives), a diabetes type, a duration of diabetes diagnosis, and the like, and any combination thereof.
In some embodiments, determining the one or more physiological parameters (kgly, kage, and/or K) for a subject may be performed using a physiological parameter analysis system.
In some embodiments, the instructions include receiving inputs 216 (e.g., one or more RPI values, one or more glucose levels, one or more HbA1c levels, one or more physiological parameters (kgly, kage, and/or K) previously determined, or more other subject-specific parameters, and/or one or more times associated with any of the foregoing), determining outputs 218 (e.g., one or more physiological parameters (kgly, kage, and/or K), an error associated with the one or more physiological parameters, one or more parameters or characteristics for a subject's personalized diabetes management (e.g., cHbA1c, a personalized-target glucose range, an average-target glucose level, a supplement or medication dosage, among other parameters or characteristics), a matched group of participants, and the like), and communicating the outputs 218. In some embodiments, communication of the inputs 216 may be via a user-interface (which may be part of a display), a data network, a server/cloud, another device, a computer, or any combination thereof, for example. In some embodiments, communication of the outputs 218 may be to a display (which may be part of a user-interface), a data network, a server/cloud, another device, a computer, or any combination thereof, for example.
A “machine-readable medium”, as the term is used herein, includes any mechanism that can store information in a form accessible by a machine (a machine may be, for example, a computer, network device, cellular phone, personal digital assistant (PDA), manufacturing tool, any device with one or more processors, and the like). For example, a machine-accessible medium includes recordable/non-recordable media (e.g., read-only memory (ROM), random access memory (RAM), magnetic disk storage media, optical storage media, flash memory devices, and the like).
In some instances, the one or more processors 212 and the one or more machine-readable storage media 214 may be in a single device (e.g., a computer, network device, cellular phone, PDA, an analyte monitor, and the like).
In some embodiments, a physiological parameter analysis system may include other components.
The physiological parameter analysis system 311 includes health monitoring device 14320 with subject interface 14320A and analysis module 14320B. The health monitoring device 14320 is, or may be, operatively coupled to data network 14322. Also provided in physiological parameter analysis system 311 is a glucose monitor 324 (e.g., in vivo and/or in vitro (ex vivo) devices or system) and a data processing terminal/personal computer (PC) 326, each operatively coupled to health monitoring device 14320 and/or data network 14322. Further shown in
In certain embodiments, analysis module 14320B is programmed or configured to perform physiological parameter analysis and, optionally, other analyses (e.g., cHbA1c, personalized target glucose range, and others described herein). As illustrated, analysis module 14320B is a portion of the health monitoring device 14320 (e.g., executed by a processor therein). However, the analysis module 14320B may alternatively be associated with one or more of server/cloud 328, glucose monitor 324, and/or data processing terminal/PC 326. For example, one or more of server/cloud 328, glucose monitor 324, and/or data processing terminal/PC 326 may comprise a machine-readable storage medium (or media) with a set of instructions that cause one or more processors to execute the set of instructions corresponding to the analysis module 14320B.
While the health monitoring device 14320, the data processing terminal/PC 326, and the glucose monitor 324 are illustrated as each operatively coupled to the data network 14322 for communication to/from the server/cloud 328, one or more of the health monitoring device 14320, the data processing terminal/PC 326, and the glucose monitor 324 can be programmed or configured to directly communicate with the server/cloud 328, bypassing the data network 14322. The mode of communication between the health monitoring device 14320, the data processing terminal/PC 326, the glucose monitor 324, and the data network 14322 includes one or more wireless communication, wired communication, RF communication, BLUETOOTH® communication, WiFi data communication, radio frequency identification (RFID) enabled communication, ZIGBEE® communication, or any other suitable data communication protocol, and that optionally supports data encryption/decryption, data compression, data decompression and the like.
As described in further detail below, the physiological parameter analysis can be performed by one or more of the health monitoring device 14320, data processing terminal/PC 326, glucose monitor 324, and server/cloud 328, with the resulting analysis output shared in the physiological parameter analysis system 311.
Additionally, while the glucose monitor 324, the health monitoring device 14320, and the data processing terminal/PC 326 are illustrated as each operatively coupled to each other via communication links, they can be modules within one integrated device (e.g., sensor with a processor and communication interface for transmitting/receiving and processing data).
The measurement of the plurality of glucose levels through the various time periods described herein may be done with in vivo and/or in vitro (ex vivo) methods, devices, or systems for measuring at least one analyte, such as glucose, in a bodily fluid such as in blood, interstitial fluid (ISF), subcutaneous fluid, dermal fluid, sweat, tears, saliva, or other biological fluid. In some instances, in vivo and in vitro methods, devices, or systems may be used in combination.
Examples of in vivo methods, devices, or systems measure glucose levels and optionally other analytes in blood or ISF where at least a portion of a sensor and/or sensor control device is, or can be, positioned in a subject's body (e.g., below a skin surface of a subject). Examples of devices include, but are not limited to, continuous analyte monitoring devices and flash analyte monitoring devices. Specific devices or systems are described further herein and can be found in U.S. Pat. No. 6,175,752 and U.S. Patent Application Publication No. 2011/0213225, the entire disclosures of each of which are incorporated herein by reference for all purposes. [0079] In vitro methods, devices, or systems (including those that are entirely non-invasive) include sensors that contact the bodily fluid outside the body for measuring glucose levels. For example, an in vitro system may use a meter device that has a port for receiving an analyte test strip carrying bodily fluid of the subject, which can be analyzed to determine the subject's glucose level in the bodily fluid. Additional devices and systems are described further below.
As described above the frequency and duration of measuring the glucose levels may vary from, on average, about 3 times daily (e.g., about every 8 hours) to about 14,400 times daily (e.g., about every 10 seconds) (or more often) and from about a few days to over about 300 days, respectively.
Once glucose levels are measured, the glucose levels may be used to determine the one or more physiological parameters (kgly, kage, and/or K) and, in some instances, other analyses (e.g., cHbA1c, personalized target glucose range, and others described herein). In some instances, such analyses may be performed with a physiological parameter analysis system. For example, referring back to
The measurement of one or more HbA1c levels at the various times described herein may be according to any suitable method. Typically, HbA1c levels are measured in a laboratory using a blood sample from a subject. Examples of laboratory tests include, but are not limited to, a chromatography-based assay, an antibody-based immunoassay, and an enzyme-based immunoassay. HbA1c levels may also be measured using electrochemical biosensors.
The frequency of HbA1c level measurements may vary from, on average, monthly to annually (or less often if the average glucose level of the subject is stable).
Calculated HbA1c (cHbA1c)
Referring back to
After one or more physiological parameters (kgly, kage, and/or K) are calculated, a plurality of glucose measurements may be taken for a following time period and used for calculating HbA1c during and/or at the end of the following time period. For example, referring back to
A subject's cHbA1c may be determined for several successive time periods based on the one or more physiological parameters (kgly, kage, and/or K) determined with the most recently measured HbA1c level, the most recently measured RPI value(s), and the intervening measurements of glucose levels. The RPI value may be measured periodically (e.g., every 6 months to a year) to recalculate kage. The most recent RPI value or an average of two or more RPI values can be used in the calculation. The HbA1c may be measured periodically (e.g., every 6 months to a year) to recalculate the one or more physiological parameters. The time between remeasuring the RPI value and the measured HbA1c may depend on (1) the consistency of the measurements of glucose levels, (2) the frequency of the measurements of glucose levels, (3) a subject's and corresponding family's diabetic history, (4) the length of time the subject has been diagnosed with diabetes, (5) changes to a subject's personalized diabetes management (e.g., changes in medications/dosages, changes in diet, changes in exercise, and the like), (6) the presence of a disease or disorder that effects kmat (e.g., anemia, a bone marrow disease, a genetic condition, an immune system disorder, and combinations thereof). For example, a subject with consistent measurements of glucose levels (e.g., a [G] with less than 5% variation) and frequent measurements of glucose levels (e.g., continuous glucose monitoring) may measure HbA1c levels less frequently than a subject who recently (e.g., within the last 6 months) changed the dosage of a glycation medication, even with consistent and frequent measurements of glucose levels.
Two cHbA1c levels are illustrated, but one or more cHbA1c levels may be displayed on the report, including a line that continuously tracks cHbA1c. Alternatively, the output 218 of the physiological parameter analysis system 211 may include a single number for a current or most recently calculated cHbA1c, a table corresponding to the data of
In some instances, the cHbA1c may be compared to a previous cHbA1c and/or a previous measured HbA1c level to monitor the efficacy of a subject's personalized diabetes management. For example, if a diet and/or exercise plan is being implemented as part of a subject's personalized diabetes management, with all other factors (e.g., medication and other diseases) equal, then changes in the cHbA1c compared to the previous cHbA1c and/or the previous measured HbA1c level may indicate if the diet and/or exercise plan is effective, ineffective, or a gradation therebetween.
In some instances, the cHbA1c may be compared to a previous cHbA1c and/or a previous measured HbA1c level to determine if another HbA1c measurement should be taken. For example, in the absence of significant glucose profile change, if the cHbA1c changes by 0.5 percentage units or more (e.g., changes from 7.0% to 6.5% or from 7.5% to 6.8%) as compared to the previous cHbA1c and/or the previous measured HbA1c level, another measured HbA1c level may be tested.
In some instances, a comparison of the cHbA1c to a previous cHbA1c and/or a previous measured HbA1c level may indicate if an abnormal or diseased physiological condition is present. For example, if a subject has maintained a cHbA1c and/or measured HbA1c level for an extended period of time, then if a change in cHbA1c is identified with no other obvious causes, the subject may have a new abnormal or diseased physiological condition. Indications of what that new abnormal or diseased physiological condition may be gleaned from the one or more physiological parameters (kgly, kage, and/or K). Details of abnormal or diseased physiological conditions relative to the one or more physiological parameters are discussed further herein.
Typically, the glucose levels in subjects with diabetes are preferably maintained between 54 mg/dL and 180 mg/dl_. However, the kinetic model described herein (see Equation 6) illustrates that intracellular glucose levels are dependent on physiological parameters kgly, kage, and K. Therefore, a measured glucose level may not correspond to the actual physiological conditions in a subject. For example, a subject with a higher than normal K may glycate glucose more readily. Therefore, a 180 mg/dl_measured glucose level may be too high for the subject and, in the long run, potentially worsen the effects of the subject's diabetes. In another example, a subject with a lower than normal kgly may glycate glucose to a lesser degree. Accordingly, at a 54 mg/dL glucose level, the subject's intracellular glucose level may be much lower making the subject feel weak and, in the long term, lead to the subject being hypoglycemic.
Using the accepted normal lower glucose limit (LGL) and the accepted normal HbA1c upper limit (AU), equations for a personalized lower glucose limit (GL) (Equation 13) and a personalized upper glucose limit (GU) (Equation 14) can be derived from Equation 6.
Equation 13 is based on kgly because the lower limit of a glucose range is based on an equivalent intracellular glucose level. Equation 14 is based on K because the upper limit of a glucose range is based on an equivalent extracellular glucose level (e.g., the accepted normal HbA1c upper limit).
The currently accepted values for the foregoing are LGL=54 mg/dL, kge{circumflex over ( )}=6.2*10−6 dL*mg−1*day−1, and AU=0.08 (i.e., 8%). Using the currently accepted values Equations 15 and 16 can be derived.
For example, a subject with a K of 4.5*10˜4 dL/mg and a kgly of 7.0*106 dL*mg−1*day1 may have a personalized-target glucose range of about 48±3.4 mg/dl_ to about 193±13.5 mg/dl_. Therefore, the subject may have a wider range of acceptable glucose levels than the currently practiced glucose range.
In another example, a subject with a K of 6.5*10−4 dL/mg and a kgly of 6.0*106 dL*mg−1*day1 may have a personalized-target glucose range of about 56±3.5 mg/dL to about 134±10 mg/dL. With the much-reduced upper glucose level limit, the subject's personalized diabetes management may include more frequent glucose level measurements and/or medications to stay substantially within the personalized-target glucose range.
In yet another example, a subject with a K of 5.0*10−4 dL/mg and a kgly of 5.0*10−6 dL*mg−1*day{circumflex over ( )} may have a personalized-target glucose range of about 67±4.5 mg/dL to about 174±12 mg/dL. This subject is more sensitive to lower glucose levels and may feel weak, hungry, dizzy, etc. more often if the currently practiced glucose range (54 mg/dL and 180 mg/dL) were used.
While the foregoing examples all include a personalized glucose lower limit and a personalized glucose upper limit, a personalized-target glucose range may alternatively include only the personalized glucose lower limit or the personalized glucose upper limit and use the currently practiced glucose lower or upper limit as the other value in the personalized-target glucose range.
The personalized-target glucose range may be determined and/or implemented in a physiological parameter analysis system. For example, a set of instructions or program associated with a glucose monitor and/or health monitoring device that determines a therapy (e.g., an insulin dosage) may use a personalized-target glucose range in such analysis. In some instances, a display or subject interface with display may display the personalized-target glucose range.
The personalized-target glucose range may be updated over time as one or more physiological parameters are recalculated.
In some instances, a subject's personalized diabetes management may include having an HbA1c value target for a future time point. For example, referring to
In some embodiments, a physiological parameter analysis system may determine an average glucose level for the subject during time period 108 and, in some instances, display the average glucose level and/or the target average glucose level. The subject may use the current average glucose level and the target average glucose level to self-monitor their progress over time period 108. In some instances, the current average glucose level may be transmitted (periodically or regularly) to a health care provider using a physiological parameter analysis system for monitoring and/or analysis.
The personalized-target average glucose may be updated over time as one or more physiological parameters are recalculated.
Data from 148 type 2 and 139 type 1 subjects enrolled in two previous clinical studies having six months of continuous glucose monitoring were analyzed. Only 90 subjects had sufficient data to meet the kinetic model assumptions described above having data with no continuous glucose data gap 12 hours or longer. Study participants had three HbA1c measurements, on days 1, 100 (±5 days), and 200 (±5 days), as well as frequent subcutaneous glucose monitoring throughout the analysis time period, which allowed for analysis of two independent data sections (days 1-100 and days 101-200) per participant.
The first data section (days 1-100) was used to numerically estimate individual kgly and kage, which allows prospective calculation of ending cHbA1c of the second data section (days 101-200). This ending cHbA1c can be compared with the observed ending HbA1c to validate the kinetic model described herein. For comparison, an estimated HbA1c for the second data section was calculated based on (1) 14-day mean and (2) 14-day weighted average glucose converted by the accepted regression model from the Ale-Derived Average Glucose (ADAG) study, which both assume kgly is a constant, which as discussed previously is the currently accepted method of relating HbA1c to glucose measurements.
The
Using the kinetic model of the present disclosure, a relationship between K (dL/mg) and mean glucose level target (mg/dL) is illustrated in
Additional details of methods, devices, and systems for determining physiological parameters related to the kinetics of red blood cell glycation, elimination, and generation within the body of a subject are set forth in U.S. Patent Publication No. 2018/0235524 to Dunn et al., International Publication No. WO2020/086934 to Xu, International Publication No. WO2021/108419 to Xu, International Publication No. WO2021/108431 to Xu, U.S. Provisional Patent Application No. 62/939,970, U.S. Provisional Patent Application No. 63/015,044, U.S. Provisional Patent Application No. 63/081,599, U.S. Provisional Patent Application No. 62/939,956, each of which is incorporated by reference in its entirety herein. Such physiological parameters can be used, for example, to calculate personalized glucose metrics or personalized analyte measurements: a more reliable calculated HbA1c (cHbA1c) or glucose-derived A1c (GD-A1c), adjusted HbA1c (aHbA1c or personalized A1c), adjusted cA1c (or cHbA1c adjusted by Kage), and/or a personalized target glucose range, among other things, for subject-personalized diagnoses, treatments, and/or monitoring protocols.
For purpose of illustration, not limitation, the processor in the reader device is configured to run the models described herein to calculate the physiological parameters and personalized glucose metrics. As embodied herein, the laboratory A1c measurement required to calculate the physiological parameters and the personalized glucose metrics can be received by the reader device, for example, not limitation, by using a camera (for example, not limitation, such as one built into the reader device) to scan a QR code which includes the relevant laboratory A1c data. As embodied herein, the laboratory A1c measurement can be received or retrieved by the reader device from a cloud-based database. As embodied herein, a home testing kit can be used to measure HbA1c in a blood sample and can be entered into the reader device by the user, instead of a laboratory A1c measurement.
A1c-glucose discordance confounds and adversely affects subject care. For example, as shown in Table 1 below, subjects A, B, and C have the same laboratory measured A1c levels but different mean glucose levels (125 mg/dL, 154 mg/dL, and 188 mg/dL, respectively). Similarly, subjects B, D, and E have same mean glucose level of 154 mg/dL, but different laboratory measured A1c (7.0%, 6.0%, and 8.0%, respectively). This information is represented graphically in
Models described herein allow quantitative removal of red blood cell artifacts, thereby improving hyperglycemia risk assessment. For example, for illustration not limitation, consider the subjects A-E with the following characteristics:
As can be seen in Table 2, subjects A, B, and C have different RBC lifespan (or as measured in days (123, 87, and 110, respectively) but the same laboratory measured Ale of 7.0%. Based on the different RBC lifespan, subject A, B, and C's personalized A1c or adjusted A1c, as measured by the models disclosed above, is 6, 8.4, and 6.7, respectively. Since the laboratory measured A1c for the three subjects is the same, their respective medical providers may view all three as diabetic and prescribe the same treatment regimen based on these values. However, because of their differing RBC lifespan, their glycemic control is in fact very different, as demonstrated by their starkly different personalized A1c. Indeed, based on their respective personalized A1c, subject A is pre-diabetic (based on personalized A1c of 6.0), subject B is clearly diabetic (based on personalized A1c of 8.4), and subject C is also diabetic (based on personalized A1c of 6.7). Accordingly, subjects A, B, and C in fact may need different treatment regimens. Similarly, although subject D may be viewed as pre-diabetic based on laboratory A1c of 6.0, they would be considered diabetic based on personalized A1c of 7.1. Further, subject E would be considered diabetic based on a laboratory A1c of 8.0, but would be considered pre-diabetic based on personalized A1c of 6.9.
Referring first to
In addition, according to some embodiments, sensor results GUI 235 also includes a second portion 237 comprising a graphical representation of analyte data. In particular, second portion 237 includes an analyte trend graph reflecting an analyte concentration, as shown by the y-axis, over a predetermined time period, as shown by the x-axis. According to embodiments, second portion 237 can include a personalized analyte trend graph reflecting a personalized analyte concentration, as determined using a kinetic model as disclosed herein below, as shown by the y-axis, over a predetermined time period, as shown by the x-axis. In some embodiments, the predetermined time period can be shown in five-minute increments, with a total of twelve hours of data. Those of skill in the art will appreciate, however, that other time increments and durations of analyte data can be utilized and are fully within the scope of this disclosure. Second portion 237 can also include a point 239 on the analyte trend graph to indicate the current analyte concentration value, a shaded green area 240 to indicate a target analyte range, and two dotted lines 238a and 238b to indicate, respectively, a high analyte threshold and a low analyte threshold. According to embodiments, point 239 on a personalized analyte trend graph can indicate the current personalized concentration value, shaded green area 240 to indicate a personalized target analyte range, and/or two dotted lines 238a and 238b to indicate, respectively, a personalized high analyte threshold and a personalized low analyte threshold. According to some embodiments, GUI 235 can also include a third portion 241 comprising a graphical indicator and textual information representative of a remaining amount of sensor life.
Referring next to
According to another aspect of the embodiments, data on sensor results GUI 245 is automatically updated or refreshed according to an update interval (e.g., every second, every minute, every 5 minutes, etc.). For example, according to many of the embodiments, as analyte data is received by the reader device, sensor results GUI 245 will update: (1) the current analyte concentration value shown in first portion 236, and (2) the analyte trend line 241 and current analyte data point 239 show in second portion 237. Furthermore, in some embodiments, the automatically updating analyte data can cause older historical analyte data (e.g., in the left portion of analyte trend line 241) to no longer be displayed. According to embodiments, current analyte concentration value can include current personalized current value, analyte trend line 241 can include personalized analyte trend line 241, and current analyte data point 239 can include a current personalized analyte data point 239.
Turning to
Referring to
According to another aspect of the embodiments, “Custom” Time-in-Ranges view 305A also includes a user-definable custom target range 312 that includes an actionable “edit” link that allows a user to define and/or change the custom target range. As shown in “Custom” Time-in-Ranges view 305A, the custom target range 312 has been defined as a glucose range between 100 and 140 mg/dL and corresponds with third bar 316 of the plurality of bars. Those of skill in the art will also appreciate that, in other embodiments, more than one range can be adjustable by the user, and such embodiments are fully within the scope of this disclosure. According to embodiments, custom target range 312 can include custom personalized target ranges.
Referring to
According to one aspect of the embodiment shown in
Turning to
Referring next to
Referring next to
Furthermore, although
In some embodiments, HCPs can receive a report of the user's frequency of interaction and a history of the patient's recorded metabolic parameters (e.g., estimated HbA1c levels, time in range of 70-180 mg/dL, etc.). If an HCP sees certain patients in their practice are less engaged than others, the HCPs can focus their efforts on improving engagement in users/patients that are less engaged than others. HCPs can benefit from more cumulative statistics (such as average glucose views per day, average glucose views before/after meals, average glucose views on “in-control” vs. “out-of-control” days or time of day) which may be obtained from the record of user's interaction frequency with the analyte monitoring systems and which can be used to understand why a patient may not be realizing expected gains from the analyte monitoring system. If an HCP sees that a patient is not benefiting as expected from the analyte monitoring system, they may recommend an increased level of interaction (e.g., increase interaction target level). Accordingly, an HCP can change the predetermined target level of interaction.
In some embodiments, caregivers can receive a report of the user's frequency of interaction. In turn, caregivers may be able to nudge the user to improve interaction with the analyte monitoring system. The caregivers may be able to use the data to better understand and improve their level of engagement with the user's analyte monitoring systems or alter therapy decisions.
According to some embodiments, for example, a sensor usage interface can include the visual display of one or more “view” metrics, each of which can be indicative of a measure of user engagement or interaction with the analyte monitoring system. A “view” can comprise, for example, an instance in which a sensor results interface is rendered or brought into the foreground (e.g., in certain embodiments, to view any of the GUI described herein). In some embodiments, the update interval as described above, data on sensor results GUI 245 is automatically updated or refreshed according to an update interval (e.g., every second, every minute, every 5 minutes, etc.). As such, a “view” can comprise one instance per update interval in which a sensor results interface is rendered or brought into the foreground. For example, if the update interval is every minute, rendering or bringing into the foreground the sensor results GUI 245 several times in that minute would only comprise one “view.” Similarly, if the sensor results GUI 245 is rendered or brought into the foreground for 20 continuous minutes, data on the senor results GUI 245 would be updated 20 times (i.e., once every minute). However, this would only constitute 20 “views” (i.e., one “view” per update interval). Similarly, if the update interval is every five minutes, rendering or bringing into the foreground the sensor results GUI 245 several times in those five minutes would only comprise one “view.” If the sensor results interface is rendered or brought into the foreground for 20 continuous minutes, this would constitute 4 “views” (i.e., one “view” each for each of the four five-minute intervals). According to other embodiments, a “view” can be defined as an instance when a user views a sensor results interface with a valid sensor reading for the first time in a sensor lifecount. According to disclosed embodiments, user can receive a notification, as described below, indicating when an instance of rendering or brining into the foreground the sensor results GUI is not counted as a “view.” For example, the user can receive a visual notification indicating such as “Results have not updated,” or “View does not count,” or “Please check glucose level again.” In some embodiments, the user can receive a check-in for each instance which counts as a “view,” as described in greater detail below.
According to disclosed embodiments, the one or more processors can be configured to record no more than one instance of user operation of the reader device during a defined time period. For example, and not limitation, a defined time period can include an hour. A person of ordinary skill in the art would understand defined time period to include any appropriate period of time, such as, one hour, two hours, three hours, 30 minutes, 15 minutes, etc.
According to some embodiments, a “view” can comprise, for example, a visual notification (e.g., prompt, alert, alarm, pop-up window, banner notification, etc.). In some embodiments, the visual notification can include an alarm condition, an analyte level measurement associated with the alarm condition, and a trend indicator associated with the alarm condition. For example, Analyte Level/Trend Alert GUIs, such as those embodiments depicted in
In some embodiments, a sensor user interface can include a visual display of a “scan” metric indicative of another measure of user engagement or interaction with the analyte monitoring system. A “scan” can comprise, for example, an instance in which a user uses a reader device (e.g., smart phone, dedicated reader, etc.) to scan a sensor control device, such as, for example, in a Flash Analyte Monitoring system. As described above in connection with “views”, a “scan” can comprise one instance per update interval in a user uses a reader device to scan a sensor control device.
According to another aspect of the embodiments, although predetermined time period 508 is shown as one week, those of skill in the art will recognize that other predetermined time periods (e.g., 3 days, 14 days, 30 days) can be utilized. In addition, predetermined time period 508 can be a discrete period of time—with a start date and an end date—as shown in sensor usage interface 500 of
According to embodiments,
Referring next to
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It will be understood by those of skill in the art that any of the GUIs, reports interfaces, or portions thereof, as described herein, are meant to be illustrative only, and that the individual elements, or any combination of elements, depicted and/or described for a particular embodiment or figure are freely combinable with any elements, or any combination of elements, depicted and/or described with respect to any of the other embodiments.
Described herein are example embodiments of digital interfaces for analyte monitoring systems. In accordance with the disclosed subject matter, a digital interface can comprise a series of instructions, routines, subroutines, and/or algorithms, such as software and/or firmware stored in a non-transitory memory, executed by one or more processors of one or more devices in an analyte monitoring system, wherein the instructions, routines, subroutines, or algorithms are configured to enable certain functions and inter-device communications. As an initial matter, it will be understood by those of skill in the art that the digital interfaces described herein can comprise instructions stored in a non-transitory memory of a sensor control device 102, reader device 120, local computer system 170, trusted computer system 180, and/or any other device or system that is part of, or in communication with, analyte monitoring system 100, as described with respect to
Example embodiments of methods for data backfilling in an analyte monitoring system will now be described. In accordance with the disclosed subject matter, gaps in analyte data and other information can result from interruptions to communication links between various devices in an analyte monitoring system 100. These interruptions can occur, for example, from a device being powered off (e.g., a user's smart phone runs out of battery), or a first device temporarily moving out of a wireless communication range from a second device (e.g., a user wearing sensor control device 102 inadvertently leaves her smart phone at home when she goes to work). As a result of these interruptions, reader device 120 may not receive analyte data and other information from sensor control device 102. It would thus be beneficial to have a robust and flexible method for data backfilling in an analyte monitoring system to ensure that once a communication link is re-established, each analyte monitoring device can receive a complete set of data, as intended.
At Step 604, a disconnection event or condition occurs that causes an interruption to the communication link between the first device and the second device. As described above, the disconnection event can result from the second device (e.g., reader device 120, smart phone, etc.) running out of battery power or being powered off manually by a user. A disconnection event can also result from the first device being moved outside a wireless communication range of the second device, from the presence of a physical barrier that obstructs the first device and/or the second device, or from anything that otherwise prevents wireless communications from occurring between the first and second devices.
At Step 606, the communication link is re-established between the first device and the second device (e.g., the first device comes back into the wireless communication range of the second device). Upon reconnection, the second device requests historical analyte data according to a last lifecount metric for which data was received. In accordance with the disclosed subject matter, the lifecount metric can be a numeric value that is incremented and tracked on the second device in units of time (e.g., minutes), and is indicative of an amount of time elapsed since the sensor control device was activated. For example, in some embodiments, after the second device (e.g., reader device 120, smart phone, etc.) re-establishes a Bluetooth wireless communication link with the first device (e.g., sensor control device 120), the second device can determine the last lifecount metric for which data was received. Then, according to some embodiments, the second device can send to the first device a request for historical analyte data and other information having a lifecount metric greater than the determined last lifecount metric for which data was received.
In some embodiments, the second device can send a request to the first device for historical analyte data or other information associated with a specific lifecount range, instead of requesting historical analyte data associated with a lifecount metric greater than a determined last lifecount metric for which data was received.
At Step 608, upon receiving the request, the first device retrieves the requested historical analyte data from storage (e.g., non-transitory memory of sensor control device 102), and subsequently transmits the requested historical analyte data to the second device at Step 610. At Step 612, upon receiving the requested historical analyte data, the second device stores the requested historical analyte data in storage (e.g., non-transitory memory of reader device 120). In accordance with the disclosed subject matter, when the requested historical analyte data is stored by the second device, it can be stored along with the associated lifecount metric. In some embodiments, the second device can also output the requested historical analyte data to a display of the second device, such as, for example to a glucose trend graph of a sensor results GUI, such as those described with respect to
Furthermore, those of skill in the art will appreciate that the method of data backfilling can be implemented between multiple and various devices in an analyte monitoring system, wherein the devices are in wired or wireless communication with each other.
According to another aspect of the embodiments, the plurality of upload triggers can include (but is not limited to) one or more of the following: activation of sensor control device 102; user entry or deletion of a note or log entry; a wireless communication link (e.g., Bluetooth) reestablished between reader device 120 and sensor control device 102; alarm threshold changed; alarm presentation, update, or dismissal; internet connection re-established; reader device 120 restarted; a receipt of one or more current glucose readings from sensor control device 102; sensor control device 120 terminated; signal loss alarm presentation, update, or dismissal; signal loss alarm is toggled on/offt view of sensor results screen GUI; or user sign-in into cloud-based platform.
According to another aspect of the embodiments, in order to track the transmission and receipt of data between devices, reader device 120 can “mark” analyte data and other information that is to be transmitted to trusted computer system 180. In some embodiments, for example, upon receipt of the analyte data and other information, trusted computer system 180 can send a return response to reader device 120, to acknowledge that the analyte data and other information has been successfully received. Subsequently, reader device 120 can mark the data as successfully sent. In some embodiments, the analyte data and other information can be marked by reader device 120 both prior to being sent and after receipt of the return response. In other embodiments, the analyte data and other information can be marked by reader device 120 only after receipt of the return response from trusted computer system 180.
Referring to
At Step 626, the communication link between reader device 120 and trusted computer system 180 (as well as the internet) is re-established, which is one of the plurality of upload triggers. Subsequently, reader device 120 determines the last successful transmission of data to trusted computer system 180 based on the previously marked analyte data and other information sent. Then, at Step 628, reader device 120 can transmit analyte data and other information not yet received by trusted computer system 180. At Step 630, reader device 120 receives acknowledgement of successful receipt of analyte data and other information from trusted computer system 180.
Although
In addition to data backfilling, example embodiments of methods for aggregating disconnect and reconnect events for wireless communication links in an analyte monitoring system are described. In accordance with the disclosed subject matter, there can be numerous and wide-ranging causes for interruptions to wireless communication links between various devices in an analyte monitoring system. Some causes can be technical in nature (e.g., a reader device is outside a sensor control device's wireless communication range), while other causes can relate to user behavior (e.g., a user leaving his or her reader device at home). In order to improve connectivity and data integrity in analyte monitoring systems, it would therefore be beneficial to gather information regarding the disconnect and reconnect events between various devices in an analyte monitoring system.
At Step 642, analyte data and other information are communicated between reader device 120 and trusted computer system 180 based on a plurality of upload triggers, such as those previously described with respect to method 620 of
Referring still to
According to some embodiments, the disconnect and reconnect times can be stored in non-transitory memory of trusted computer system 180, such as in a database, and aggregated with the disconnect and reconnect times collected from other analyte monitoring systems. In some embodiments, the disconnect and reconnect times can also be transmitted to and stored on a different cloud-based platform or server from trusted computer system 180 that stores analyte data. In still other embodiments, the disconnect and reconnect times can be anonymized.
In addition, those of skill in the art will recognize that method 640 can be utilized to collect disconnect and reconnect times between other devices in an analyte monitoring system, including, for example: between reader device 120 and trusted computer system 180; between reader device 120 and a wearable computing device (e.g., smart watch, smart glasses); between reader device 120 and a medication delivery device (e.g., insulin pump, insulin pen); between sensor control device 102 and a wearable computing device; between sensor control device 102 and a medication delivery device; and any other combination of devices within an analyte monitoring system. Those of skill in the art will further appreciate that method 640 can be utilized to analyze disconnect and reconnect times for different wireless communication protocols, such as, for example, Bluetooth or Bluetooth Low Energy, NFC, 802.11x, UHF, cellular connectivity, or any other standard or proprietary wireless communication protocol.
Example embodiments of methods for improved expired and/or failed sensor transmissions in an analyte monitoring system will now be described. In accordance with the disclosed subject matter, expired or failed sensor conditions detected by a sensor control device 102 can trigger alerts on reader device 120. However, if the reader device 120 is in “airplane mode,” powered off, outside a wireless communication range of sensor control device 102, or otherwise unable to wirelessly communicate with the sensor control device 102, then the reader device 120 may not receive these alerts. This can cause the user to miss information such as, for example, the need to promptly replace a sensor control device 102. Failure to take action on a detected sensor fault can also lead to the user being unaware of adverse glucose conditions (e.g., hypoglycemia and/or hyperglycemia) due to a terminated sensor.
Referring again to
At Step 708, sensor control device 102 can be configured to monitor for a return response or acknowledgment of receipt of the indication of the sensor fault condition from reader device 120. In some embodiments, for example, a return response or acknowledgement of receipt can be generated by reader device 120 when a user dismisses an alert on the reader device 120 relating to the indication of the sensor fault condition, or otherwise responds to a prompt for confirmation of the indication of the sensor fault condition. If a return response or acknowledgement of receipt of the indication of the sensor fault condition is received by sensor control device 102, then at Step 714, sensor control device 102 can enter either a storage state or a termination state. According to some embodiments, in the storage state, the sensor control device 102 is placed in a low-power mode, and the sensor control device 102 is capable of being re-activated by a reader device 120. By contrast, in the termination state, the sensor control device 102 cannot be re-activated and must be removed and replaced.
If a receipt of the fault condition indication is not received by sensor control device 102, then at Step 710, the sensor control device 102 will stop transmitting the fault condition indication after a first predetermined time period. In some embodiments, for example, the first predetermined time period can be one of: one hour, two hours, five hours, etc. Subsequently, at Step 712, if a receipt of the fault condition indication is still not received by sensor control device 102, then at Step 712, the sensor control device 102 will also stop allowing for data backfilling after a second predetermined time period. In some embodiments, for example, the second predetermined time period can be one of: twenty-four hours, forty-eight hours, etc. Sensor control device 102 then enters a storage state or a termination state at Step 714.
By allowing sensor control device 102 to continue transmissions of sensor fault conditions for a predetermined time period, the embodiments of this disclosure mitigate the risk of unreceived sensor fault alerts. In addition, although the embodiments described above are in reference to a sensor control device 102 in communication with a reader device 120, those of skill in the art will recognize that indications of sensor fault conditions can also be transmitted between a sensor control device 102 and other types of mobile computing devices, such as, for example, wearable computing devices (e.g., smart watches, smart glasses) or tablet computing devices.
Example embodiments of methods for merging data received from one or more analyte monitoring systems will now be described. As described earlier with respect to
Referring still to
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Although
Example embodiments of methods for sensor transitioning will now be described. In accordance with the disclosed subject matter, as mobile computing and wearable technologies continue to advance at a rapid pace and become more ubiquitous, users are more likely to replace or upgrade their smart phones more frequently. In the context of analyte monitoring systems, it would therefore be beneficial to have sensor transitioning methods to allow a user to continue using a previously activated sensor control device with a new smart phone. In addition, it would also be beneficial to ensure that historical analyte data from the sensor control device could be backfilled to the new smart phone (and subsequently uploaded to the trusted computer system) in a user-friendly and secure manner.
Referring again to
If the user confirms login, then at Step 908, the user's credentials are sent to trusted computer system 180 and subsequently verified. In addition, according to some embodiments, the device ID can also be transmitted from the reader device 120 to trusted computer system 180 and stored in a non-transitory memory of trusted computer system 180. According to some embodiments, for example, in response to receiving the device ID, trusted computer system 180 can update a device ID field associated with the user's record in a database.
After the user credentials are verified by trusted computer system 180, at Step 910, the user is prompted by the app to scan the already-activated sensor control device 102. In accordance with the disclosed subject matter, the scan can comprise bringing the reader device 120 in close proximity to sensor control device 102, and causing the reader device 120 to transmit one or more wireless interrogation signals according to a first wireless communication protocol. In some embodiments, for example, the first wireless communication protocol can be a Near Field Communication (NFC) wireless communication protocol. Those of skill in the art, however, will recognize that other wireless communication protocols can be implemented (e.g., infrared, UHF, 802.11x, etc.). An example embodiment of GUI 950 for prompting the user to scan the already-activated sensor control device 102 is shown in
Referring still to
At Step 914, reader device 120 initiates a pairing sequence via the second wireless communication protocol (e.g., Bluetooth or Bluetooth Low Energy) with sensor control device 102. Subsequently, at Step 916, sensor control device 102 completes the pairing sequence with reader device 120. At Step 918, sensor control device 102 can begin sending current glucose data to reader device 120 according to the second wireless communication protocol. In some embodiments, for example, current glucose data can be wirelessly transmitted to reader device 120 at a predetermined interval (e.g., every minute, every two minutes, every five minutes).
Referring still to
Upon receipt of the request at Step 922, sensor control device 102 can retrieve historical glucose data from a non-transitory memory and transmit it to reader device 120. In turn, at Step 924, reader device 120 can store the received historical glucose data in a non-transitory memory. In addition, according to some embodiments, reader device 120 can also display the current and/or historical glucose data in the app (e.g., on a sensor results screen). In this regard, a new reader can display all available analyte data for the full wear duration of a sensor control device. In some embodiments, reader device 120 can also transmit the current and/or historical glucose data to trusted computer system 180. At Step 926, the received glucose data can be stored in a non-transitory memory (e.g., a database) of trusted computer system 180.
In some embodiments, the received glucose data can also be de-duplicated prior to storage in non-transitory memory.
Example embodiments of autonomous check sensor and replace sensor system alarms, and methods relating thereto, will now be described. In accordance with the disclosed subject matter, certain adverse conditions affecting the operation of the analyte sensor and sensor electronics can be detectable by the sensor control device. For example, an improperly inserted analyte sensor can be detected if an average glucose level measurement over a predetermined period of time is determined to be below an insertion failure threshold. Due to its small form factor and a limited power capacity, however, the sensor control device may not have sufficient alarming capabilities. As such, it would be advantageous for the sensor control device to transmit indications of adverse conditions to another device, such as a reader device (e.g., smart phone), to alert the user of those conditions.
According to another aspect of the embodiments, if a wireless communication link is established between sensor control device 102 and reader device 120, then reader device 120 will receive the check sensor indicator at Step 1008. In response to receiving the check sensor indicator, reader device 120 will display a check sensor system alarm at Step 1010.
Subsequently, at Step 1011, reader device 120 drops sensor control device 102. In accordance with the disclosed subject matter, for example, Step 1011 can comprise one or more of: terminating an existing wireless communication link with sensor control device 102; unpairing from sensor control device 102; revoking an authorization or digital certificate associated with sensor control device 102; creating or modifying a record stored on reader device 120 to indicate that sensor control device 102 is in a storage state; or transmitting an update to trusted computer system 180 to indicate that sensor control device 102 is in a storage state.
Referring back to
Although method 1000 of
At Step 1104, in response to the detection of a sensor termination condition, sensor control device 102 stops taking glucose measurements. At Step 1106, sensor control device 102 generates a replace sensor indicator and transmits it via wireless communication circuitry to reader device 120. Subsequently, at Step 1112, sensor control device 102 will continue to transmit the replace sensor indicator while determining whether a replace sensor indicator receipt has been received from reader device 102. In accordance with the disclosed subject matter, sensor control device 102 can continue to transmit the replace sensor indicator until either: (1) a predetermined waiting period has elapsed (Step 1113), or (2) a receipt of the replace sensor indicator is received (Step 1112) and sensor control device 102 has successfully transmitted backfill data (Steps 1116, 1120) to reader device 120.
Referring still to
At Step 1114, after displaying the replace sensor system alarm and transmitting the replace sensor indicator receipt, reader device 120 can then request historical glucose data from sensor control device 102. At Step 1116, sensor control device 102 can collect and send to reader device 120 the requested historical glucose data. In accordance with the disclosed subject matter, the step of requesting, collecting, and communicating historical glucose data can comprise a data backfilling routine, such as the methods described with respect to
Referring again to
At Step 1120, sensor control device 102 receives the historical glucose data received receipt. Subsequently, at Step 1122, sensor control device 102 stops the transmission of the replace sensor indicator and, at Step 1124, sensor control device 102 can enter into a termination state in which sensor control device 102 does not take glucose measurements and the wireless communication circuitry is either de-activated or in a dormant mode. In accordance with the disclosed subject matter, when in a termination state, sensor control device 102 cannot be re-activated by reader device 120.
Although method 1100 of
Example embodiments of reports comprising a plurality of interfaces will now be described. In accordance with the disclosed subject matter, a report including a plurality of the interfaces disclosed herein may be presented to a user. In accordance with the disclosed subject matter, the interfaces can include any combination of measured interfaces based on current or measured analyte values, physiological parameter interfaces based on the physiological parameters disclosed herein, and personalized interfaces based on personalized glucose metrics disclosed herein.
In view of the above and in accordance with the disclosed subject matter, a glucose monitoring system is provided comprising a sensor control device, comprising an analyte sensor coupled with sensor electronics and configured to transmit data indicative of an analyte level of a subject, and a reader device. The reader device of the disclosed subject matter comprises a wireless communication circuitry configured to receive the data indicative of the analyte level and a glycated hemoglobin level for the subject, a non-transitory memory, and at least one processor. The processor is communicatively coupled to the non-transitory memory and the analyte sensor and configured to calculate a plurality of personalized glucose metrics for the subject using at least one physiological parameter and at least one of the received data indicative of the analyte level or the received glycated hemoglobin level, and display, on a display of the reader device, a report comprising a plurality of interfaces including at least two or more of the received data indicative of the analyte level, the received glycated hemoglobin level, or the calculated plurality of personalized glucose metrics, wherein the plurality of interfaces comprising the report are based on a user type. According to embodiments, the at least one physiological parameter is selected from the group consisting of: a red blood cell glucose uptake, a red blood cell lifespan, a red blood cell glycation rate constant, a red blood cell generation rate constant, a red blood cell elimination constant, and an apparent glycation constant. For example, not limitation, in further embodiments, the plurality of interfaces includes the at least one physiological parameter for the subject.
According to embodiments, contents of a report may vary based on different user types (for example, not limitation, subjects, health care providers, caretakers, etc.). As embodied herein, the plurality of interfaces comprising the report are predetermined based on the user type or can be selected by the user. According to embodiment, the user type includes a health care professional. For example, without limitation, in a further embodiment, the plurality of interfaces includes a glucose monitoring data interface, a glycated hemoglobin interface, a personalized A1c interface, a personalized glucose interface, a personalized average glucose, and a personalized time in range interface. According to embodiment, the user type includes the subject. For example, without limitation, in a further embodiment, the plurality of interfaces a glucose monitoring data interface, a glycated hemoglobin interface, a mean glucose interface, and a time in range interface.
According to embodiments, subjects using the analyte monitoring systems can only view graphical interfaces displaying measured analyte measurements, or personalized analyte measurements, but not both. For example, it can be beneficial to minimize confusion by showing graphical interfaces with slightly different data (such as between measured and personalized). As embodied herein, the selection of which interfaces can be included in a report is dependent on whether the personalized glucose metrics have been approved or designated for research purposes or clinical purposes by the appropriate regulatory authority.
According to embodiments, personalized glucose metrics can include one or more of a personalized A1c or adjusted A1c, glucose-determined A1c or calculated A1c, personalized glucose, personalized average glucose, and personalized time in rage. According to embodiments, at least one processor is configured to calculate a plurality of personalized glucose targets corresponding to the calculated plurality of personalized glucose metrics. According to embodiments, the plurality of interfaces further includes the plurality of personalized glucose targets. According to embodiments, personalized glucose targets can include one or more of personalized glucose target range and personalized target average glucose. According to embodiments, personalized glucose target range can include a personalized lower glucose limit and/or a personalized upper glucose limit.
As embodied herein, as shown in
As embodied herein, as can be seen in
According to embodiment disclosed herein, measured interfaces can include, for example, not limitation, a glucose monitoring data interface 2401 and HbA1c interface 2402, as shown in
According to embodiment disclosed herein, physiological parameter interfaces can include for example, not limitation, red blood cell glucose uptake interface 2501 and red blood cell lifespan interface 2502, as shown in
According to embodiment disclosed herein, personalized interfaces can include for example, not limitation, personalized glucose interface 2503, personalized A1c interface 2504, personalized 14-day mean glucose interface 2505, and personalized time in ranges interface 2506, as shown in
According to embodiment disclosed herein, personalized A1c interface 2504 can include a graphical representation of the subject's adjusted or personalized A1c (shown as a dots 2504a) and adjusted cHbA1c (shown as curve fit 2504c), calculated using the models as described herein and in WO2021/108419 and WO2020/086934 to Xu, which are incorporated by reference in its entirety herein. As embodied herein, personalized A1c interface 2504 can include a graphical representation (shown as solid line) of target HbA1c 2504b (for example, not limitation, 6.5%).
According to embodiment disclosed herein, personalized 14-day mean glucose interface 2505 can include a mean glucose interface 1403 including a graphical representation of personalized 14-day mean glucose (141 mg/dL as shown) over a predetermined period of time. As embodied herein, as shown in
According to embodiment disclosed herein, personalized time in ranges interface 2506, can include a graphical representation of personalized time in range metrics (78% over 180 mg/dL and 3% below 70 mg/dL, as shown) over a predetermined period of time.
As embodied herein, as can be seen in
According to embodiments disclosed herein, reports 1400 or 1500 can include a variety of measured interfaces, physiological parameter interfaces, or personalized interfaces based on user type. For example, health care providers (HCPs) and caretakers may benefit from seeing a comparison of measured interfaces and personalized interfaces, for example, to assess how much the two differ and to assess diagnosis and treatment options accordingly. As such, in an embodiment, contents of a report for an HCP can include a predetermined set of measured interfaces, physiological parameter interfaces, and personalized interfaces, for example, not limitation, as shown in report 1500. According to embodiments, HCPs can have the greatest access to information, including measured analyte measurements, personalized analyte measurement, and physiological parameters (for example, not limitation, RBC glucose uptake and RBC lifespan as shown in
As embodied herein, a user (e.g., the subject, a HCP, a caretaker, an insurance provider, etc.) may select which interfaces comprise the report. For example, not limitation, the user may choose any combination of measured interfaces, personalized interfaces, and physiological parameter interface disclosed herein.
According to an embodiment, a user can select whether to view a sensor result interface as disclosed herein displaying measured analyte measurement (for example, not limitation, such as those shown in
According to embodiments, the combined data can be used in conjunction with any of the graphical user interfaces described above. According to embodiments of the present disclosure, a user (e.g., a user, health care provider, caretaker, etc.) can personalize any of the graphical interfaces described above. Furthermore, an Ambulatory Glucose Profile Report (“AGP Report”) (for example, not limitation, such as the one proposed by the International Diabetes Center (“IDC”), which is incorporated by reference in its entirety and be found on the website, http://www.agpreport.org/agp/agpreports) can be modified to include any of the graphical interfaces or personalized metrics described herein. For example, not limitation, IDC's AGP Report Version 5 can be modified by replacing Glucose Management Indicator (GMI) with Personalized A1c. Furthermore, a graphical interface for reporting Personalized A1c can be achieved by combining any of the graphical components described herein. For example, in one embodiment, a graphical user interface 3000 can include at least the Time-in-Ranges GUI 340 as depicted in
According to
As disclosed in U.S. patent application Ser. Nos. 17/832,537 and 18/052,805, which are incorporated by reference in their entirety, HbA1c or HbA1c Target measurement can be adjusted by a user's Apparent Glycation Ration (“AGR”) (also referred to as “personalized A1c factor” or “personalized HbA1c factor”). For example, Table 3 shows an “adjusted” HbA1c target measurement based on AGR. More specifically, as can be seen in Table 3, an Ale target of 6.0 adjusted by AGR of 60 provides an adjusted A1c target is 5.5. Similarly, an A1c target of 6.0 adjusted by AGR of 65 provides an adjusted A1c target of 6.0. Alternatively, a measured A1c value can be similarly adjusted using the AGR to provide an adjusted Ale value (or a personalized Ale value). Presenting this information to subjects and health care providers can help them make more accurate and informed diabetes diagnosis and treatment based at least on the subject's individual demographic metrics and/or physiology.
Thus, by measuring A1c, determining a personalized A1c factor, and applying the factor to the measured A1c, a personalized A1c can be determined.
While the disclosed subject matter is described herein in terms of certain illustrations and examples, those skilled in the art will recognize that various modifications and improvements may be made to the disclosed subject matter without departing from the scope thereof. Moreover, although individual features of one embodiment of the disclosed subject matter may be discussed herein or shown in the drawings of one embodiment and not in other embodiments, it should be apparent that individual features of one embodiment may be combined with one or more features of another embodiment or features from a plurality of embodiments.
In addition to the specific embodiments claimed below, the disclosed subject matter is also directed to other embodiments having any other possible combination of the dependent features claimed below and those disclosed above. As such, the particular features presented in the dependent claims and disclosed above can be combined with each other in other manners within the scope of the disclosed subject matter such that the disclosed subject matter should be recognized as also specifically directed to other embodiments having any other possible combinations. Thus, the foregoing description of specific embodiments of the disclosed subject matter has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosed subject matter to those embodiments disclosed.
The description herein merely illustrates the principles of the disclosed subject matter. Various modifications and alterations to the described embodiments will be apparent to those skilled in the art in view of the teachings herein. Accordingly, the disclosure herein is intended to be illustrative, but not limiting, of the scope of the disclosed subject matter.
This application claims the benefit, under 35 U.S.C. § 119(e), of U.S. Provisional Patent Application No. 63/279,509, filed Nov. 15, 2021, which is incorporated herein by reference in its entirety and for all purposes.
Filing Document | Filing Date | Country | Kind |
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PCT/US2022/049824 | 11/14/2022 | WO |
Number | Date | Country | |
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63279509 | Nov 2021 | US |